This disclosure relates generally to hybrid tracking systems, and more particularly to a hybrid optical and electromagnetic (EM) tracking system utilizing combined light emitting diode (LED) and magnetoresistance sensors.
Medical practitioners, such as interventional radiologists, surgeons, and other medical professionals, often rely upon tracking or navigation systems when performing a medical procedure. Such systems may provide positioning and orientation information for a medical instrument or implant with respect to the patient or a reference coordinate system, for example. A medical practitioner may refer to the tracking system to ascertain the position and orientation of the medical instrument when the instrument is not within the practitioner's line of sight with regard to the patient's anatomy, or with respect to non-visual information relative to the patient. A tracking system may also aid in pre-surgical planning.
A tracking system allows the medical practitioner to visualize the patient's anatomy and track the position and orientation of the instrument. The medical practitioner may use the tracking system to determine when the instrument or implant is positioned in a desired location or oriented in a particular direction. The medical practitioner may locate and operate on, or provide therapy to, a desired or injured area while avoiding other structures. Increased precision in locating medical instruments within a patient may provide for a less invasive medical procedure by facilitating improved control over smaller, flexible instruments having less impact on the patient. Improved control and precision with smaller, more refined instruments may also reduce risks associated with more invasive procedures such as open surgery.
Tracking systems may be optical, ultrasonic, inertial, EM, or sonic, for example. Generally, each system includes its own advantages and disadvantages. For example, optical tracking is typically considered the most accurate tracking technology. However, optical tracking requires a line of sight. During the course of a surgical procedure, a line of sight path may become impossible to achieve. If the surgeon relies on optical tracking alone, navigation of the instrument or implant may be temporarily unavailable.
At such a point during a medical procedure, the surgeon may wish to employ another tracking technology, such as an EM tracking system. EM tracking systems allow for a surgeon to track a position and/or orientation of one sensor relative to another, without requiring a line of sight. However, due to electromagnetic interference caused by, among other things, metal objects in the operating environment, EM tracking systems may not always be the most accurate of the available tracking systems. Thus, at another point during the procedure, the surgeon may wish to again switch from the EM tracking system to another system.
While some current systems may allow for a surgeon to employ more than one tracking technology during a medical procedure, such systems typically do not allow for a dynamic change of tracking technologies. Further, this is achieved by providing various tracking systems along with a switch that will allow the clinician to select the appropriate tracking technology. Each tracking technology may be located at different location and the solution suggests combining existing the tracking systems to allow a surgeon to switch from one tracking technology to another in real time.
As mentioned earlier, at some point during a procedure, one or more unused tracking technologies may be more accurate than the currently used technology. At that point, the surgeon may wish to use a different tracking technology. If the surgeon is switching from one tracking system to another to use a different tracking technology, the issue of signal interference and calibration become significant. The calibration needs to be done based on the location of each tracking system and this might affect the quality of hybrid tracking systems. Thus instead of switching among different tracking systems, it will be beneficial to provided a tracking sensor unit incorporating different tracking technologies.
Therefore, a need exists for a hybrid tracking system for use in navigation of instruments and/or implants during medical, surgical and interventional procedures. Such a hybrid tracking system may provide multiple tracking technologies simultaneously during a medical, surgical and interventional procedure to assist in the accuracy of navigation instruments and/or implants during the procedure.